c. AD 1000 Leif Eriksson is the first European to set foot in North America

c. 1400 Native tribes move into the southwest

1492 Christopher Columbus sails west from Spain for Asia and lands in the West Indies

1513 Ponce de León claims Florida for Spain

1519–21 Hernán Cortés conquers the Aztec Empire

1532 Francisco Pizarro conquers the Inca Empire

1585–87 Two unsuccessful attempts are made to colonize Roanoke Island

1607 Jamestown founded

1620 Mayflower compact; Pilgrims found Plymouth

1621 First Thanksgiving

1660 King Charles II of England assigns land to be sold to colonists

1692 Salem witch trials

1754 Outbreak of French and Indian War

1763 Treaty of Paris ends French claims in North America

1779 Boston Massacre

1773 Tea Act; Rebellious colonists stage the Boston Tea Party

1774 The 13 colonies form First Continental Congress

1775–83 American Revolution begins at Lexington and Concord; ends after British surrender at Yorktown

July 4, 1776 Declaration of Independence signed

1781 Articles of Confederation ratified

1787 Constitution signed

1789 George Washington elected first US president

1791 Bill of Rights ratified

1803 Louisiana Purchase doubles land area of US

1812–14 US at war with Great Britain; British burn Washington, D.C.; “Star-Spangled Banner” written

1820 Missouri Compromise signed in attempt to avoid crisis over slavery

1823 Monroe Doctrine

1830 Indian Removal Act creates “Indian territories”

1840 Telegraph first used

1841 Oregon trail opens

1846 US war against Mexico; US borders extended to Pacific Ocean

1849 California Gold Rush

1861 Civil War erupts when southern states secede from Union, forming Confederate States of America

1863 Battle of Gettysburg; Gettysburg Address; Emancipation Proclamation

1865 13th Amendment abolishes slavery

1865 Lee surrenders to Grant; President Lincoln assassinated

1867 Reconstruction Act

1868 14th Amendment grants citizenship to African Americans

1869 Union Pacific and Central Pacific railroads meet at Promontory Point

1870 15th Amendment gives African Americans the right to vote

1876 Alexander Graham Bell invents the telephone

1879 Thomas Edison makes the electric light bulb

1882 Chinese Exclusion Act

1886 Haymarket riot; American Federation of Labor organized

1890 Frontier closes; massacre of American Indians at Wounded Knee

1898 Spanish-American War; US acquires the Philippines, Puerto Rico, and Hawaii

1903 First flight by Wright brothers at Kitty Hawk

1913 16th Amendment places federal tax on income

1914 Panama Canal opens

1915 German U-boat sinks the Lusitania

1916 Child Labor Act

1917 US enters World War I; end of Progressivism

1918 End of World War I

1919 18th Amendment begins Prohibition

1920 19th Amendment gives women the vote

1927 Charles Lindbergh makes flight across Atlantic; first “talkie” released

1929 Stock market crashes; Great Depression

1933 Great Plains become the “Dust Bowl”; President Roosevelt launches the New Deal

1939 Germany invades Czechoslovakia and Poland; Great Britain and France declare war on Germany

Dec. 7, 1941 Pearl Harbor attacked; US enters war

1942 Relocation of Japanese-Americans begins; Bataan Death March; Battles of Coral Sea and Midway

June 6, 1944 D-Day

May 8, 1945 Germany surrenders

Aug. 6, 1945 US drops atomic bomb on Hiroshima

Aug. 9, 1945 US drops atomic bomb on Nagasaki

Aug. 15, 1945 Japan surrenders

1948 Marshall Plan implemented; Berlin airlift

1950 McCarthy hearings begin; start of Korean War

1954 Supreme Court ruling on Brown v. Board of Education

1955 Montgomery bus boycott

1957 Sputnik I launched

1958 First American satellite goes into orbit

1961 Bay of Pigs fiasco

1962 Cuban Missile Crisis

1963 March on Washington, D.C.; Dr. Martin Luther King, Jr. delivers “I Have a Dream” speech

Nov. 22, 1963 President Kennedy assassinated

1965 American troops sent to Vietnam

1968 My Lai massacre

Apr. 4, 1968 Dr. Martin Luther King, Jr. assassinated; violence erupts in 125 cities

1969 Apollo 11 crew lands on the Moon

1972 Watergate break-in

1974 President Nixon resigns

1975 US personnel evacuated from Saigon; South Vietnam surrenders

1979 Global oil shortage; gas rationing

1979 Iranian rebels seize US Embassy

1981 Scientists identify Acquired Immune Deficiency Syndrome (AIDS)

Jan. 28, 1986 Space shuttle Challenger explodes

1986 Iran-Contra scandal

1989 Berlin Wall torn down; fall of communism in eastern Europe begins

1991 US leads coalition in Operation Desert Storm

1992 US troops join UN mission in Somalia

1995 Oklahoma City bombing

1998 President Clinton impeached, later acquitted

Sept. 11, 2001 Two hijacked planes destroy the World Trade Center towers; a third hits the Pentagon; a fourth crashes in a field in Pennsylvania

2001 US and Britain bomb Afghanistan; Taliban government collapses

2003 US and British forces invade Iraq; Baath party government under Saddam Hussein collapses

The framers of the Constitution created a federal government with three branches so that any two could prevent the third from gaining too much power: